Hi, I have a few websites with different contents selling same services. They also have unique ip address. I want to setup google analytics, if I use same google account, will google penalize my websites? because google knows they have same owner?

I doubt Google will penalize you for using the same analytics account, of course you should have a different tracking number for each site in the account though so you can track each one separately.

If they are all in the same account then Google can tell that the sites are related so if you link between the sites, then they will be able to tell the sites are related or possibly owned by the same person/entity. Would Google give less value to links between the sites because they are owned by the same people, I am not sure? Some people will say it is possible since they may consider these links as not being freely given and manipulated, but no one knows for sure.

I have personally signed up multiple related sites under the same analytics account without any discernible issues. If you want to decrease the amount of ties between related sites you manage then I would sign up under different analytics accounts. Google may still be able to determine that the same owner manages both sites though (if you login to the different google analytics accounts from the same computer, same ip address, then they could find a tie between them if they wanted to).

Actually these websites don't link to each other but only to compete for higher ranking on google and other search engines. Will there be a problem if they are built on same sitebuilder software? Meaning they will have same structure but only different contents. The situation is similar to wordpress where many people use wordpress and they have same software and structure as well. Any thoughts?

There is no reason for Google to penalize websites owned by the same person/company, using the same site builders or Google account if you are not conducting malicious practice, whether business or non-business (for example, questionable SEO tactics) on these websites.

That is just like Wayne said, however, if you are going to engage in link building (well, a bit aggressive for example) and if you have a lot of websites then it is probably a good idea to separate your main sites and the sites which you use to link building into different Google Analytics accounts in order to avoid suspicion from the search engines.